video_core: Remove unnecessary enum class casting in logging messages

fmt now automatically prints the numeric value of an enum class member
by default, so we don't need to use casts any more.

Reduces the line noise a bit.

src/video_core/textures/convert.cpp

@@ -82,7 +82,7 @@ void ConvertFromHostToGuest(u8* data, PixelFormat pixel_format, u32 width, u32 h
                             bool convert_astc, bool convert_s8z24) {
     if (convert_astc && IsPixelFormatASTC(pixel_format)) {
         LOG_CRITICAL(HW_GPU, "Conversion of format {} after texture flushing is not implemented",
-                     static_cast<u32>(pixel_format));
+                     pixel_format);
         UNREACHABLE();
 
     } else if (convert_s8z24 && pixel_format == PixelFormat::S8_UINT_D24_UNORM) {